U.S. Pat. No. 7,455,616 to Beltkowski is a carrier output device. The device contains a spindle which is usually defined as the shaft type part that supports the inner raceways of the main bearings. It is the shaft part that the tapered bearing cone sits on. The '616 patent is a hub output device. The spindle is fixed to the machine frame and the entire housing rotates around the spindle. The wheel is connected to the housing.
U.S. Pat. No. 6,852,061 to Schoon, the inventor of the instant application, states, in the Abstract, as follows: “A new, useful and compact wheel motor drive arrangement for applications on such construction equipment as scissor lifts and other similar scaffolding equipment where hydraulically driven systems have historically been used to provide power to the wheels to move the equipment is disclosed. An electric motor is mounted to a spindle bracket which is pivotably connected to the frame of the equipment to allow the unit to be pivoted around a vertical axis for steering purposes. A gear reducing planetary gear system is mounted around the drive shaft of the motor is (sic) positioned totally within the rotating wheel hub. The output ring gear of the planetary gear system is integrally formed to the interior of the wheel hub so that there is a direct application through the planetary gear system to the wheel hub to provide greater efficiency.”
There is a need for clean, environmentally green, compact electric wheel drive assemblies for relatively light, medium speed vehicles. Some example applications are zero-turn lawn mowers, utility vehicles, and sweepers. Currently non-axle vehicles are driven with low speed hydraulic motors which are directly connected to the wheels. Hydraulic systems have many undesirable features such as noise, leaks, and relatively poor efficiency.